Dana Spicer Drive Axles ®

Dana® Spicer®
Drive Axles
P/N: SHAIS168
Ring and Pinion Tooth Contact Pattern Information
Affected Models: All Dana Drive Axle Models
Dana drive axles require adjustment of the ring gear and pinion tooth contact at overhaul or anytime the axle has been
disassembled. Most axles require the same distinctive pattern, described in our service publications.
After differential preload and gear backlash adjustments are complete, check the tooth contact pattern and adjust if
necessary. Tooth contact patterns are a function of the relative positions of the ring gear and the pinion. An improper
pattern will require a relocation of either or both. Always adjust pinion position first, if necessary, then the ring gear
position. Always check backlash when done.
New Gearing
Paint ring gear with marking compound and roll the gear to
obtain a contact pattern as shown in the photograph. The
length of the pattern in a unloaded condition is
approximately one-half to two-thirds of the ring gear tooth
in most models and ratios.
Pattern should range from just clear of the toe end to about
3/8” off the toe end. The pattern should be evenly centered
between tooth top land and root.
New Gearing
Used Gearing
Used gearing may not display the round, even contact
pattern found in new gear sets. The gear may have a
“pocket” at the heel end of pattern. The more “use” a gear
has had, the more dominate characteristic of the pattern.
Adjust used gearing so as to display the same contact
pattern observed before disassembly. A correct pattern is up
slightly off the toe and centers evenly along the face width
between the top land and the root. Otherwise, the length
and shape of the pattern are highly variable and are
considered acceptable as long as there is some pattern on
toe end of the tooth.
Used Gearing
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SHAIS168 – Ring and Pinion Contact Pattern Information
If necessary, adjust the contact pattern by moving the ring gear or drive pinion. Ring gear position
controls the backlash. This adjustment moves the pattern along the face width or up and down the
gear tooth. Pinion position is determined by the size of the shims behind the pinion bearing cage,
and controls tooth depth contact.
These adjustments are interrelated. As a result, they must be considered together even though
the pattern is altered by two distinct operations. When making adjustments, first adjust the pinion,
then the backlash.
Incorrect Pattern - Adjust Pinion Position
Pattern to close to
tooth top land and
off center.
Pattern to close to
tooth root.
Remove Shim
Add Shim
If the contact pattern shows incorrect tooth depth contact, change drive pinion position by altering the shim
pack. Used gearing should achieve proper contact with the same shims removed form the axle at disassembly.
Always recheck backlash after shim changes.
Incorrect Pattern - Adjust Backlash
Pattern is more
than 3/8” off the
toe of tooth.
Decrease Backlash
Pattern is running
off the toe of the
tooth.
Increase Backlash
Increase backlash by loosening the bearing adjuster on the tooth side of the ring gear several notches.
Loosen the opposite adjuster one notch. Return to adjuster on the tooth side of the ring gear and tighten adjuster
until it contacts the bearing cup. Continue tightening the same adjuster 2 or 3 notches. Recheck backlash.
Decrease Backlash by loosening the bearing adjuster on the tooth side of the ring gear several notches.
Tighten the opposite adjuster one notch. Return the adjuster on the tooth side of the gear and tighten adjuster
until it contacts the bearing cup. Continue tightening the same adjuster 2 to 3 notches. Recheck backlash.
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SHAIS168 – Ring and Pinion Contact Pattern Information
Refer to this illustration for proper ring gear nomenclature.
Tooth Depth
Heel
Top land
Face
Root
Toe
For spec’ing or service assistance, call 1-800-826-HELP (4357) 24 hours a day, 7 days a week,
(Mexico: 8-332-1515). Or visit our web site at: http://www.roadranger.com
SHAIS168
May 2005
Printed in U.S.A.
Copyright Dana Corporation, 2005
All Rights Reserved.
www.dana.com/heavytruck
Dana Corporation
Commercial Vehicle Axle Division
P.O. Box 4097
Kalamazoo, MI 49003
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